多聚磷酸改性沥青结合料高低温流变特性∗

摘要

通过沥青3大指标实验、动态剪切流变实验(DSR)和小梁弯曲蠕变劲度实验(BBR),研究不同掺量多聚磷酸(PPA)单独改性沥青的高低温流变性能,并与基质沥青和 SBS改性沥青进行对比.结果表明,随 PPA 掺量的增加,PPA改性沥青软化点升高,针入度降低,PPA 对沥青高温性能改善较为明显；DSR 实验证明,可以用1％的PPA代替4％的SBS来改善沥青的高温性能,并且 PPA掺量几乎每增加0．5％,高温PG等级就提高一个等级；对于PPA单独改性沥青低温性能,在正温区内得到的趋势不能外延到负温区内,延度实验表明,在正温区内,随PPA掺量增加,PPA改性沥青低温性能负面影响增大,SBS改性沥青的低温性能优于不同掺量的 PPA 改性沥青；BBR实验证明了在负温区内,不同掺量的PPA改性沥青和SBS改性沥青在不同温度区间内表现出的低温抵抗变形能力不同.%Through three index test,dynamic shear rheological test (DSR)and trabecular bending creep stiff-ness test (BBR),studied different proportion of polyphosphoric acid (PPA)separate modified asphalt the high and low temperature rheological properties,and compared with the matrix asphalt and SBS modified asphalt. The results show that:with the increase of PPA dosage,PPA separate modified asphalt softening point im-prove,penetration decreases,PPA is improve more obvious to the physical properties of asphaDSR tests in-dicate that,the high temperature performance can use 1%PPA instead of 4%SBS modified asphalt,almost ev-ery 0.5% increase in dosage of PPA,the high temperature PG level will raise a level;For PPA modified asphalt performance at low temperature,the trend of temperature in the positive zone can't extension to the negative temperature zone;Ductility test experiments,In the positive temperature zone,with the increase of the admix-ture of coal with PPA,the negative impact of PPA modified asphalt performance at low temperature increased, the low temperature performance of SBS modified asphalt is better than that of PPA modified asphaBBR tests indicate that,In the negative temperature zone,matrix asphalt,PPA modified asphalt and SBS4% modified as-phalt in different temperature range of the low temperature resistance to deformation ability is different.